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<b>DbEnv::set_feedback</b>
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<b><pre>
#include &lt;db_cxx.h&gt;
<p>
int
DbEnv::set_feedback(void (*db_feedback_fcn)(DbEnv *dbenv, int opcode, int percent));
</pre></b>
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<b>Description: DbEnv::set_feedback</b>
<p>Some operations performed by the Berkeley DB library can take non-trivial
amounts of time.  The DbEnv::set_feedback method can be used by applications
to monitor progress within these operations.  When an operation is
likely to take a long time, Berkeley DB will call the specified callback
function with progress information.</p>
<p>It is up to the callback function to display this information in an
appropriate manner.</p>
<p>The DbEnv::set_feedback method configures operations performed using the specified
<a href="../api_cxx/env_class.html">DbEnv</a> handle
<p>The DbEnv::set_feedback method may be called at any time during the life of the
application.</p>
<p>The DbEnv::set_feedback method
either returns a non-zero error value
or throws an exception that encapsulates a non-zero error value on
failure, and returns 0 on success.
</p>
<b>Parameters</b> <br>
 <b>db_feedback_fcn</b><ul compact><li>The <b>db_feedback_fcn</b> parameter is the application-specified
feedback function called to report Berkeley DB operation progress.  The
callback function must take three parameters:
<br>
<b><b>dbenv</b></b><ul compact><li>The <b>dbenv</b> parameter is a reference to the enclosing database
environment.</ul>
<b><b>opcode</b></b><ul compact><li>The <b>opcode</b> parameter is an operation code.  The <b>opcode</b>
parameter may take on any of the following values:
<br>
<b><a name="DB_RECOVER">DB_RECOVER</a></b><ul compact><li>The environment is being recovered.</ul>
<br></ul>
<b><b>percent</b></b><ul compact><li>The <b>percent</b> parameter is the percent of the operation that has
been completed, specified as an integer value between 0 and 100.</ul>
<br></ul>
<p>Berkeley DB is not re-entrant.  Callback functions should not attempt to make
library calls (for example, to release locks or close open handles).
Re-entering Berkeley DB is not guaranteed to work correctly, and the results
are undefined.</p>
<br>
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<br><b>Class</b>
<a href="../api_cxx/env_class.html">DbEnv</a>
<br><b>See Also</b>
<a href="../api_cxx/env_list.html">Database Environments and Related Methods</a>
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